Terminal position assurance system for electrical connectors

Abstract: A terminal position assurance system is provided for an electrical connector (10,14) which includes a dielectric housing (18,50) having a terminal-receiving passage (24,74) into which a terminal (12,16) is inserted in an insertion direction (A,B) to a fully inserted position. A latch surface (22b,76b) is formed in the housing adjacent the passage and facing in the insertion direction. A bendable tab (42,72) is provided on the terminal and is adapted to be bent against the latch surface. The bendable tab is structured to be bent about an axis (46,80) generally parallel to the insertion direction to move an edge portion (42a,72a) of the tab to a position over the latch surface when the terminal is in its fully inserted position.

Description: Field of the Invention This invention relates to an electrical connector of the kind referred-to in the preamble to claim 1, and to a method of ensuring proper positioning of a female terminal. Background of the Invention An electrical terminal of that kind is disclosed in US-A-5 147 228. US-A-3 178 672 shows bending of tabs to fix a connector in a wall structure. Terminal position assurance systems heretofore employed in electrical connectors often require the use of a separate component to provide the terminal positioning assurance. In other words, after terminals are inserted into terminal-receiving passages in a connector housing, a separate component is inserted into an opening or openings in the housing which communicates with the terminal-receiving passages. In essence, this separate component provides a secondary lock on the terminals as well as some indication that all of the terminals are in their proper positions. Problems are encountered with the use of separate terminal position assurance components in that they are more susceptible to leakage or arc tracking. In addition, because of the additional separate components, a user of such systems must maintain an inventory of not only the connector housings and the terminals, but also the separate terminal position assurance or locking components. The potential of leakage or arc tracking is created because the separate components require an opening in the housing for access to a portion of a terminal. This invention is directed to solving the above problems and providing an improved terminal position assurance system which does not require separate locking components and, in fact, uses an integral portion of each terminal as a secondary locking feature which provides the terminal position assurance system. The integral portion herein is provided by a bendable tab. Bendable tabs have been used heretofore for locking terminals in respective terminal-receiving passages within connector housings. However, such prior art bendable tabs have not been capable of providing a terminal positioning assurance system. More particularly, the bendable tabs of the prior art are generally planar and are bent about axes or fold lines which are generally perpendicular to the insertion direction of the terminals. Such bendable tabs are bent to overlie locking surfaces of the connector housing adjacent the terminal-receiving passages. In other words, the tabs are bent about axes or fold lines generally parallel to such surfaces. Consequently, a particular terminal might not be fully inserted into its respective terminal-receiving passage, but the bendable tab still is capable of being bent to overlie the locking surface, notwithstanding the fact that the terminal is not properly positioned in the housing. The present invention utilizes a simple bendable tab which not only can be considered a terminal locking feature but also provides a terminal-position assurance means for the terminal. Summary of Invention An object, therefore, of the invention is to provide an electrical connector with a new and improved terminal position assurance system of the character described. The invention is defined in claims 1 and 5. In the examplary embodiment of the invention, the system is used in an electrical connector which includes a dielectric housing having a wall with a terminal-receiving passage therethrough. The wall defines first and second surfaces. A terminal is adapted to be received in the passage with a mating portion on one side of the wall and a terminating portion on the other side of the wall. Stop means are provided on the terminal for engaging the first surface of the wall to prevent the terminal from passing completely through the passage and to define a fully inserted position of the terminal. A bendable tab is provided on the terminal and is adapted to be bent against the second surface of the wall when the terminal is inserted into the passage. The invention contemplates that the bendable tab be structured to be bent about an axis perpendicular to the second surface of the wall and be positioned over the second surface when the terminal is fully positioned in the passage. More particularly, the second surface of the wall is generally flat and the tab is generally planar. The tab has an edge generally perpendicular to its bend axis, with the edge adapted for lockingly engaging the second surface when the tab is bent about the axis. Therefore, if the terminal is not inserted to its fully inserted position, the tab cannot be bent about the axis, thereby indicating that the terminal has not been fully inserted into the passage. Other objects, features and advantages of the invention will be apparent from the following detailed description taken in connection with the accompanying drawings. Brief Description of the Drawings The features of this invention which are believed to be novel are set forth with particularity in the appended claims. The invention, together with its objects and the advantages thereof, may be best understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements in the figures and in which: FIGURE 1 is a perspective view, partially cut away, of an electrical connector mounting a plurality of male terminals and embodying the concepts of the invention; FIGURE 2 is a fragmented vertical section taken generally along line 2-2 of Figure 1; FIGURE 3 is a perspective view of one of the male terminals of the connector of Figure 1; FIGURE 4 is a perspective view of an electrical connector employing a plurality of female terminals and embodying the concepts of the invention; FIGURE 5 is a fragmented vertical section taken generally along line 5-5 of Figure 4; FIGURE 6 is a perspective view of one of the female terminals of the connector of Figure 4; FIGURE 7 is a fragmented perspective view of one of the male terminals of the connector in Figure 1, with the bendable tabs in position prior to bending, along with an appropriate tool shown in phantom for effecting bending of the tabs; and FIGURE 8 is a view similar to that of Figure 7, but showing in phantom an appropriate tool for bending the tabs of one of the female terminals of the connector shown in Figure 4. Detailed Description of the Preferred Embodiment Referring to the drawings in greater detail, Figures 1-3 show an electrical connector, generally designated 10, which mounts a plurality of male terminals, generally designated 12; and Figures 4-6 show an electrical connector, generally designated 14, which mounts a plurality of female terminals, generally designated 16. Each connector 10 and 14, along with their terminals 12 and 16, respectively, embodies the terminal positioning assurance system of the invention. More particularly, connector 10 (Figs. 1-2) includes a dielectric housing, generally designated 18, having a plurality of receptacles 20 for matingly receiving a plurality of silos of a complementary mating connector, such as connector 14 in Figures 4 and 5. The base of each receptacle 20 is defined by a wall, generally designated 22, defining first and second surfaces 22a (Fig. 2) and 22b. The wall has a terminal-receiving passage 24 therethrough. Passages 25 (Fig. 1) in wall 22 simply are core-out passages used in molding housing 18. Each male terminal 12 includes a flat or generally planar blade-like mating portion 26 and a terminating portion 28. The mating portion is adapted for mating with a female terminal such as female terminal 16 in Figure 6. Terminating portion 28 includes two pairs of crimp arms 30 and 32 for termination to an electrical wire, such as an insulated conductor, generally designated 34 in Figure 2. Crimp arms 30 are crimped onto a conductor core 34a, whereas crimp arms 32 are crimped onto the outer cladding or insulation 34b of the insulated conductor. Male terminal 12 may be stamped and formed of sheet metal material and includes a pair of primary locking arms 36 which are cantilevered to define resilient distal ends 38 and rigid stop shoulders 40, for purposes described hereinafter. In addition, a pair of bendable tabs 42 project outwardly of terminal blade 26 generally coplanar therewith in the initial condition of the terminal shown in Figure 3. These blades can provide a secondary lock for the terminal, and the bendable tabs are provided as terminal position assurance devices as described hereinafter. After crimp arms 30 and 32 are crimped to terminate each terminal 12 to an insulated conductor 34, the terminal is inserted into housing 18 in the direction of arrow "A" (Fig. 2). The fully inserted position of the terminal is shown in Figure 2. It can be seen that stop shoulders 40 have engaged against first surface 22a of wall 22. In addition, primary locking arms 36 have snapped behind interior partitions 44 to prevent the terminal from backing out or away from its fully inserted position. When in such a fully inserted position, bendable tabs 42 can be used as a terminal position assurance system. More particularly, as seen best in Figure 1, but also in Figure 2, tabs 42 have been bent from their first or original positions shown in Figure 3 generally coplanar with terminal blade 26, to bent positions whereat the tabs are positioned over second surface 22b of wall 24. The tabs are bent about axes located generally at 46 in Figure 1. These axes are generally parallel to the insertion direction of the terminals as indicated by arrow "A" (Fig. 2), or the axes can be considered to extend generally perpendicular to surface 22b. Therefore, an edge 42a of each tab moves in a path over the top of surface 22b. If one of male terminals 12 is not fully positioned as shown, any attempt to bend its tabs 42 about axes 46 would not be possible, because edges 42a of the tabs will not have cleared surface 22b of wall 22. This inability to bend the tabs gives a clear indication that the terminal is not in its fully inserted position. Connector 14 and female terminals 16 in Figures 4-6 incorporate a similar "bendable tab" terminal position assurance system as described above in relation to connector 10 and male terminals 12 in Figures 1-3. Specifically, connector 14 includes a dielectric housing, generally designated 50, defining a plurality of silos 52 for mating with a plurality of receptacles of a complementary connector, such as receptacles 20 of connector 18 (Fig. 1). One of the female terminals 16 is mounted within each silo 52. As best in seen in Figure 6, each female terminal 16 includes a generally hollow mating portion 54 for mating with a male terminal, such as blade portion 26 of male terminal 12 inserted into mating female portion 54 in the direction of arrow "B". Each female terminal 16 includes a terminating portion 56 having two pairs of crimp arms 58 and 60 for crimping onto a conductor core 62 and an insulating cladding, respectively, of an insulated conductor, generally designated 66. Like male terminal 12, female terminal 16 is fabricated of stamped and formed sheet metal material, and a primary locking arm 68 is bent or formed outwardly of the terminal for snapping behind a locking shoulder 70 (Fig. 5) of housing 50 when the terminal is in its fully inserted position within its respective silo 52. As will be described in greater detail hereinafter, the terminal also includes a pair of bendable tabs 72, having lower edges 72a, to provide a terminal position assurance system for connector 14. Each female terminal 16 is inserted into a passage 74 (Fig. 5) in housing 50 and a respective one of the silos 52, in the direction of arrow "C". The passage includes a wall, generally designated 76, which defines a first surface 76a and a second surface 76b. Stop means are provided by corner bosses 77 of silos 52, the bosses having interior stop surfaces 77a. In the fully inserted positions of female terminals 16, the ends 54a of the mating portions 54 of the terminals abut against stop surfaces 77a of bosses 77. Similar to the terminal position assurance system described above in relation to connector 10 and male terminals 12 in Figures 1-3, when each female terminal 16 is inserted to its fully inserted position as shown in Figure 5, edges 72a of bendable tabs 72 are clear of second surface 76b of wall 76 within the respective passage 74 of the housing. Tabs 72 then can be bent about axes 80 (Fig. 6) generally parallel to the insertion direction "C" of the terminal, whereby the bendable tabs are positioned over the second surface 76b of wall 76. In other words, the tabs are bendable about axes 80 which extend generally perpendicular to surface 76b. Should the terminal not be fully inserted, the bendable tabs will not clear wall 76 and cannot be bent to the positions shown in Figures 4 and 5, which gives an indication that the terminal is not properly positioned. Figures 7 and 8 show various types of tools for bending the terminal position assurance tabs of male terminals 12 (Fig. 7) and female terminals 16 (Fig. 8) when the terminals are in their fully inserted positions. More particularly, referring to Figure 7, a generally cylindrical tool 82 has a pair of slots or notches 84 in its lower peripheral edge. The notches are dimensioned for embracing bendable tabs 42 of male terminal 12, as the tool is inserted downwardly into receptacle 20 of connector housing 18. With the notches embracing the bendable tabs, the tool can be rotated in either direction as indicated by double-headed arrow "D" to bend the tabs about axes 46 so that the tabs are positioned over surface 22b of wall 22. Referring to Figure 8, a tool 86 is shown in phantom and is configured as a blade, such as a blade of a small screw driver. The tool is inserted into mating portion 54 of female terminal 16 similar to the insertion of a male terminal as indicated by arrow "B" in Figure 6. Once inserted, the tool is rotated in the direction of arrow "E" to bend tabs 72 outwardly in the direction of arrows "F", whereupon the tabs will be bent from the positions shown in Figure 8 to the positions shown in Figure 4, thereby indicating that the particular female terminal has been inserted to its proper fully inserted position. Again, if any given female terminal is not fully inserted or properly positioned, tool 86 cannot bend the tabs because the tabs will not clear wall 76 (Fig. 5). It will be understood that the invention may be embodied in other specific forms without departing from the central characteristics thereof. The present examples and embodiments, therefore, are to be considered in all respects as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but solely by the scope of the appended claims.

Claims: An electrical connector (10, 14) which includes a dielectric housing (18, 50) having a wall (22, 76) with a terminal-receiving passage (24, 74) therethrough, the wall defining first (22a, 76a) and second (22b, 76b) surfaces, a terminal (12, 16) adapted to be received in the passage with a mating portion (26, 54) on one side of the wall and a terminating portion (28, 56) on the other side of the wall, stop means (40, 54a) on the terminal for engaging a stop surface (22a, 77a) of the housing to prevent the terminal from passing completely through the passage in an insertion direction toward the first surface and to define a fully inserted position of the terminal, and a bendable tab (42, 74) on the terminal and adapted to be bent against the second surface (22b, 76b) of the wall when the terminal is inserted into the passage, characterized in that said mating terminal portion (26, 54) has a forward end, said stop means (40, 54a) located at said forward end and said bendable tab (42, 72) located at said forward end are structured to be bent about an axis (46, 80) perpendicular to the second surface (22b, 76b) of the wall and are to be positioned over the second surface when the terminal is fully positioned in the passage. The electrical connector as set forth in claim 1, wherein said second surface (22b, 76b) is generally flat and said tab (42, 72) is generally planar. The electrical connector as set forth in claim 2, wherein said tab (42, 72) has an edge (42a, 72a) generally perpendicular to said axis (46, 80) and is adapted for lockingly engaging the second surface (22b, 76b) when the tab is bent about the axis. The electrical connector as set forth in claim 1, wherein said terminal mating portion (54) is female forming a generally rectangular cross section adapted to receive a male blade terminal. A method of ensuring proper positioning of a female terminal (12, 16) having a generally rectangular cross section defining a terminal mating cavity having a longitudinal axis in a dielectric housing (18, 50) of an electrical connector (10, 14), the housing having a terminal-receiving passage (24, 74) into which the terminal is inserted in an insertion direction (A, C) to a fully inserted position, comprising the steps of: providing a latch surface (22b, 76b) on the housing adjacent the passage and facing in said insertion direction; providing a bendable tab (42, 72) on the terminal, the tab being bendable about an axis (46, 80) generally parallel to said insertion direction from a first position aligned with said passage to a second position over the latch surface; inserting the terminal into the passage in said insertion direction to said fully inserted position; inserting an elongated blade like tool into said terminal mating cavity; and beinding said tab from said first position to said second position by moving the tool (86) about its longitudinal axis generally while the tool axis is congruent with the longitudinal axis of the terminal mating cavity.

Inventors: KLEMMER ROBERT A, KRZECZOWSKI RONALD S, PELOZA KIRK B, WENDT RUSSELL E, KLEMMER, ROBERT A., KRZECZOWSKI,RONALD S., PELOZA, KIRK B., WENDT, RUSSELL E.
Applicants: MOLEX INC, MOLEX INCORPORATED
Application year: 1994
Main classification: H01R13
IPC codes: H01R13